The present invention relates to a novel and useful apparatus for measuring the mobility of a tooth.
Periodontal disease is characterized by a human developing swelling of the gums which is associated with bleeding upon provocation. In addition, the gum tissue (gingiva) and jaw (alveolar) bone loss also occurs. The primary etiology of periodontal disease is linked to plaque and tartar (calculus). The end stage of periodontal disease is marked by tooth loss, bone loss, and attachment loss.
During the development of periodontal disease, teeth develop an abnormal mobility. In other words, teeth become loose relative to attachment to the jaw. In the past, the degree of looseness has been measured without any accurate instrumental devices. The standard procedure for measuring mobility consists of placement of two ends of a dental instrument on a tooth and the application of an alternating back and forth force on such instruments to initiate movement of the tooth. The degree of mobility from this method is then “eyeballed” by the dental practitioner who the guesses as to the degree of mobility.
Teeth found in the human jaw have a natural or physio-logical mobility of 0-0.25 mm. Thus, such level of natural of mobility does not indicate a disease state or a state related to a trauma. Teeth possess a natural mobility because teeth are not firmly attached directly to the jawbone, but are separated by a periodontal ligament. The periodontal ligament generally functions as a natural shock absorber.
Thus, mobility beyond 0.25 mm, indicates a trauma condition or existence of periodontal disease. A classification system, known as the Miller Scale, sorts tooth mobility into three classes. Class 1 is defined as a tooth movement or a mobility of up to 1 mm. Class 2 is defined as a horizontal movement between 1 mm and 2 mm. Finally, class 3 mobility takes place when tooth movement lies between 2 mm and 3 mm, with depressible vertical mobility.
In the past, the need to measure tooth mobility has been recognized. For example, Russian Patent 219653701, Japanese Patent 3552894 B2, Japanese Patent 3625035 B2, and Japanese Patent 4272917 B2 show devices and methods that use probes or piston that apply a force to the tooth and gages that detect the physical movement of such piston or probe.
U.S. Pat. Nos. 4,192,321, 4,470,810, and 5,680,874 show apparatuses for measuring tooth mobility in which a movable probe, positioned against a tooth, generates an electrical signal that is interpreted as an indication of movement of the tooth.
U.S. Pat. No. 5,803,730, Japanese Patent 3620979 B2, and Japanese Patent 2008048992 A show devices for measuring tooth mobility in which the movement of a contacting member on the tooth is transferred into an optical signal indicating the distance of movement of the tooth.
Russian Patent 2068242 C1 and Russian Patent 2223063 C1 show devices for indicating tooth mobility utilizing a clamping sleeve or clamp in combination with a rod to indicate tooth movement on the application of a force on the rod.
An apparatus for measuring tooth mobility and detecting the possibility of periodontal disease in a simple mechanical fashion would be a notable advance in the dental arts.